Temporal-Layer-Motivated Lambda Domain Picture Level Rate Control for Random-Access Configuration in H.265/HEVC

Rate control is a key technique for video communication systems. The aim of rate control is to transmit the best possible quality video sequences under various restrictions, such as channel bandwidth, buffer capacity, maximum time delay allowed for a given service, and so on. The <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> domain rate control technique (<inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-RC) has been integrated into the latest High Efficiency Video Coding standard (H.265/HEVC) test model, due to its accurate bit estimation and high rate-distortion performance. However, it is found that the <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-RC is not the optimal choice under the random-access configuration. When the random-access configuration is used, pictures are organized into temporal layers, where pictures in different layers are of different importance in terms of prediction. In this paper, a picture level lambda domain rate control technique for the random-access configuration in H.265/HEVC is proposed. The influence of temporal layers is effectively considered in the proposed algorithm referred to as TL-<inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-PRC. Experimental results verify that the proposed TL-<inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-PRC is efficient in coding performance and accurate in bit estimation. Compared with the <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-RC with the fixed ration bit allocation which has been implemented in the test model of H.265/HEVC (HM 14.0), TL-<inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>-PRC achieves an average reduction of 4.10% and 3.49% for slow motion and fast motion sequences, respectively, in BD-rate (Bjøntegaard-Delta bitrate) with more accurate bit estimation. The performance of different algorithms in terms of algorithm complexity and quality fluctuation are also carefully analyzed in this contribution.